"K. M. O'Donnell" is a pseudonym of Barry Malzberg's. Dwellers of the Deep is one of his "recursive" novels -- that is, it's about SF. It's some 35,000 words long. According to the ISFDB, it's his third novel, and his second Ace Double half (of 4 total). The Gates of Time was Neal Barrett's first or second novel (Kelwin also appeared in 1970), and his first of two Ace Double halves (I have also reviewed Highwood).

Dwellers of the Deep is about a young man named Izzinius Fox, a collector (not a fan!) of SF magazines in 1951. Izzy's main interest is Tremendous Stories -- an obvious analog of Astounding. (Other SF magazines mentioned include Thoughtful (F&SF?) and Thrilling (Galaxy?).) Izzy deals with a bookseller named Stuart Wiseman, who has been selling him back issues of Tremendous at perhaps inflated prices. But Izzy is also dealing with a group of aliens, who periodically take his consciousness up to their ship and pressure him to turn over his copy of the issue of Tremendous containing Cupboard's article about "A New Engineering of the Mind". (Obviously referring to L. Ron Hubbard's "Dianetics: A New Science of the Mind".) The aliens claim they will use this article benevolently to guide Earth to a new utopian future, but Fox is afraid they mean to conquer us. (For some reason the issue in question changes from the May 1950 issue (which is actually the issue of Astounding in which the first Dianetics article appeared) to the December 1946 issue as the book goes on.)

Izzinius has other concerns. For example, he is afraid of women, but there is a young woman living in his apartment building, Susan Forsythe, who keeps invading his room and trying to get him to attend meetings of the local fan group, the Solarians. Fox is also out of work, having quit his civil service job to concentrate on SF magazine collecting. The aliens are torturing him with false memories of his dead father. And his landlord is just plain weird ...

So the novel continues -- full of satire of fan politics and fan obsessions, with the occasional side trip to satire of bureaucracy. It's really pretty funny for the most part, though it may depend a bit on getting some of the fannish injokes. Not a great story by any means but basically fun stuff -- much like the previous "O'Donnell" Ace Double I reviewed, Gather in the Hall of the Planets.

In my previous review of Highwood, I covered Neal Barrett's career: short stories in Galaxy and such places beginning in 1960, and novels starting in 1970 with Kelwin and The Gates of Time, and later the Aldair books for DAW. Then, as someone once said, Barrett stood too long next to fellow Texan Howard Waldrop and just mutated. Beginning in the mid 80s he published a few novels and a number of short stories that are gloriously weird, poetic, loopily imagined -- just real neat stuff, including novels such as Through Darkest America (1986), short stories like "Ginny Sweethips' Flying Circus", "Stairs", and "Cush". His more recent work includes a number of mysteries and a couple further unusual science fantasies beginning with The Prophecy Machine in 2000.

But what about The Gates of Time? Suffice it to say, it doesn't in the least hint at the pretty worthwhile writer Barrett became. Ignoring a pointless prologue and epilogue, it opens with Luis Jarcal, the only surviving human, on a huge multi-species starship. His lover is a catlike alien, but he is soon in trouble with her husband. And the starship is in the vanguard of efforts to hold back something called "the Void". And Jarcal mysteriously becomes possessed by a strange being called N'Cil. His only friends seem to be a symbiotic pair of aliens -- the birdlike Lhis and the plantlike Quan. We are told that Earth's first attempt at a starship was swallowed, along with Earth, by the Void, only Jarcal surviving.

OK -- that could work. Then piratical evil aliens destroy the starship, only Jarcal and Lhis-Quan surviving. At the aliens' planet they encounter another human -- naturally a shockingly beautiful woman, named Sesharane. After the escape the quartet goes on the run, learning that, well, Jarcal and his N'Cil companion are fated to save the world or something and ...

Blah, blah, blah. Pretty much a case of the author making things up as he goes along. Without much concern for internal consistency (for example, we learn that Earth apparently had an extensive interstellar empire -- but wait a minute, earlier they just had one doomed starship -- is this explained? NO!) There is also such silliness as Sesharane refusing to have sexual relationships with Jarcal because, even though she loves him and he her, she is unable to have babies, so sex would be pointless. Eh? (As it happens, I just have been reading Neal Stephenson's Quicksilver, which makes much of a couple of main, heterosexual, characters engaging in rather extravagantly non-propagational sex -- not that that's a big deal or anything, but just that the contrast in attitudes really struck me.) Anyway, I really can't recommend The Gates of Time at all.